In many applications, it is desirable to convert the spatially-varying signal intensity of an input 2-D electromagnetic signal into an amplified electrical 2-D output signal having a spatially-varying output intensity distribution corresponding to that of the input electromagnetic signal. The output electrical signal in this way preserves the information content of the input electromagnetic signal, but in such a way that it may be advantageously utilized in a host of applications environments that include, but are not limited to, imaging detectors, optical signal processors, real-time adaptive optical systems, and target recognition, tracking and optical communications systems. Such 2-D conversion devices are often called upon to provide a high degree of spatial resolution, wide spectral bandwidths, fast cycle times, the capability to accommodate the heat produced by high-power output utilization devices, control of the electron energy distribution, high-current-level output signals, sensitivity to low input-intensity signal levels, and, among other things, to provide the capability to be fabricated at a reasonably low cost. Reference may be had to U.S. Pat. No. 4,481,531 for an exemplary microchannel spatial light modulator, incorporated herein by reference. The utility of the heretofore known devices has been limited in one or more of the foregoing respects.